When lung cancer subjects were segregated based on histological subtypes, the co-dominant and dominant models for the MSH6 557G > T polymorphism predicted a decreased risk of developing adenocarcinoma in subjects with the heterozygous genotype (GT) (AOR 0.6; 95% CI 0.36–1.02; p = 0.06) and the combined (GT + GG) genotype (AOR 0.56; 95% CI 0.34–0.95; p = 0.03). The gene discussed is MSH6; the disease is adenocarcinoma.